serves as an attachment for certain
muscles and tendons of the arm, neck,
chest, and back and is involved with
movements of the arm and shoulder.
scarA mark left where damaged tissue
has healed. The body repairs a lesion by
increasing collagenproduction at the site
of damage. If the edges of a lesion are
brought together during healing, a nar-
row, pale scar forms; if the edges are left
apart, more extensive scarring occurs.
A hypertrophic scar is a large, unsightly
scar that sometimes develops at the site
of an infected wound; some people have
a family tendency to develop such scars.
(See also adhesion; keloid.)
scarlatinaAnother name for scarlet fever.
scarlet feverAn uncommon infectious
disease, more often seen in childhood,
that is caused by a strain of streptococcal
bacteria. Symptoms include a severe sore
throat, high fever, vomiting, and a rash
of tiny red spots on the neck and upper
trunk that spreads rapidly. The face is
flushed, except around the mouth, and
a white coating with red spots may deve-
lop on the tongue. This coating comes
off after a few days to reveal a bright red
colour. The fever then soon subsides,
the rash fades, and the skin may peel.
As with other types of streptococcal
infections, rheumatic feveror glomeru-
lonephritismay rarely develop 6 weeks
later. Treatment with antibioticsprevents
this and promotes a rapid recovery.SCAPULA
schistosome A type of fluke. Three types
of schistosome are parasites of humans,
causing different forms of schistosomiasis.
schistosomiasisA parasitic tropical dis-
ease, caused by any of 3 species of flukes
called schistosomes, and acquired from
bathing in infested water. The larval form
penetrates the bather’s skin and develops
in the body into adult flukes, which settle
in the veins of the bladder and intestines.
Eggs laid by adults provoke inflammatory
reactions; there may be bleeding and
ulceration in the bladder and intestinal
walls, and the liver may also be affected.
The first symptom is usually tingling
and an itchy rash where the flukes have
penetrated the skin. An influenza-like
illness may develop weeks later, when
the adults produce eggs. Subsequent
symptoms include blood in the urine or
faeces, abdominal or lower back pain,
and enlargement of the liver or spleen.
Complications of long-term infestation
include liver cirrhosis, bladder tumours,
and kidney failure. Treatment is with the
drug praziquantel.
schizoid personality disorderInabil-
ity to relate socially to other people.
Peoplewith this trait, which is apparent
from childhood, are often described as
“loners” and have few, if any, friends.
They are eccentric, seem to lack concern
for others, and are apparentlydetached
from normal day-to-day activities.
schizophreniaA general term for a
group of psychotic illnesses that are
characterized by disturbances in think-
ing, emotional reaction, and behaviour.
Onset can be at any age but is most
common in late adolescence and the
early 20s, and may be triggered by stress.
No causes have been identified, but
many have been implicated.It is likely
that inheritance plays a role. Disruption
of the activity of some neurotransmitters
in the brain is a possible mechanism.
Brain imaging techniques have revealed
abnormalities of structure and function
in people with schizophrenia.
Schizophrenia may begin insidiously,
with the individual becoming slowly
more withdrawn and losing motivation.
In other cases, the illness comes on
more suddenly, often in response to
external stress. The main symptoms areSCAR SCHIZOPHRENIAS
Scapula
ClavicleHumerus
SpineRib